Linkage

ABSTRACT

A mechanism for converting reciprocating linear motion to rotary motion comprises an escape wheel rotatable in equal angular increments about an axis, a pallet for rotating the wheel, and a ramp member for actuating the pallet and controlling the displacement of the wheel. The escape wheel is rotated by the sequential application of torque by the pallet to pins extending from the face of the escape wheel, and displaced radially from the axis and angularly from each other. The direction of rotation of the escape wheel can be reversed in response to a change in the path of reciprocation of the input member, and the pallet limits rotation of the wheel to the equal angular increments regardless of overtravel of the input member.

iinite tates Patent Eelrerdt Mar. 14, 1972 [54] LINKAGE George ill.Eckerdt, Rochester, N.Y.

Eastman Kodak Company, Rochester, NY.

[22] Filed: Apr. 13, 1970 [21] Appl.No.: 27,621

[72] Inventor:

[73] Assignee:

Re2 6,7 89 2/1970 Robinson etal ..74/1255 Primary Examiner-Meyer PerlinAssistant Examiner-Wesley S. Ratliff, Jr. Att0rney--Robert W. Hamptonand D. Peter Hochberg [5 7] ABSTRACT A mechanism for convertingreciprocating linear motion to rotary motion comprises an escape wheelrotatable in equal angular increments about an axis, a pallet forrotating the wheel, and a ramp member for actuating the pallet andcontrolling the displacement of the wheel. The escape wheel is rotatedby the sequential application of torque by the pallet to pins extendingfrom the face of the escape wheel, and dis placed radially from the axisand angularly from each other. The direction of rotation of the escapewheel can be reversed in response to a change in the path ofreciprocation of the input member, and the pallet limits rotation of thewheel to the equal angular increments regardless of overtravel of theinput member.

9 Claims, 4 Drawing Figures PMemefl March H4 1%?2 2 Sheets-Sheet 1GEORGE H. ECKERDT 8 W INVENTOR. BY

W a M ATTORNEYS Patented March 14, 1972 2 Sheets-Sheet 2 GEORGE H.ECKERDT INVENTOR.

ATTORNEYS LINKAGE CROSS-REFERENCE TO RELATED APPLICATION U,S. Ser. No.27,519, entitled Filmstrip Adapter to Slide Projector, filed on evendate herewith by George H. Eckerdt.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to mechanisms for converting reciprocating linearmotion to rotary motion of equal angular increments. The inventionfurther relates to devices for converting linear motion to rotary motionwherein an output member is alternatively rotated in clockwise andcounterclockwise directions depending on the direction of displacementofa linear input member.

2. Description of the Prior Art A common expedient for the conversionoflinear motion to rotary motion involves the use of pawl of claw typemembers which move in response to a linear input for successivelyengaging the teeth of a ratchet wheel to rotate the wheel, Examples ofthe latter devices are disclosed in U.S. Pat. Nos. 2,299,030 to Peebles,and 3,231,059 to Hall. Other devices, such as that taught by U.S. Pat.No. 3,411,685 to De Gennaro disclose rotary elements having cogs or pinsextending from the face thereof and engageable by drive members forrotating the member. U.S. Pat. No. 3,156,400 to Rigby discloses areciprocal plunger carrying a claw for successively engaging the pinsextending from the face of a rotatable disk for rotating the disk inuniform angular increments. Other devices well known in the art forconverting reciprocating linear motion to rotary motion includeslider-crank mechanisms, drag links, the Whitmore mechanism, the crankshaper, the offset slider crank, and the toggle mechanism.

Each of the foregoing mechanisms known in the prior art has one or moreof the following disadvantages: (a) high friction, such as results fromconstant rubbing contact between different elements in the mechanism;(b) the rotational output varies with the linear input, thus making itimpossible to achieve uniform angular displacement of the output memberwhen the linear input member is displaced by varying amounts withsuccessive operations of the device; the displacement of the rotaryoutput member is unidirectional, making it impossible or difiicult toreverse the direction of rotation when the direction of displacement ofthe input member is reversed; and (d) difficulty in varying the angulardisplacement of the output member.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an improved linkage for converting linear motion into rotarymotion which avoids the aforementioned disadvantages of the prior art.

A more specific object ofthe present invention is to provide a mechanismhaving a rotary output member which is displaceable in uniform angularincrements in response to the displacement ofa reciprocating linearinput member, with the angular displacement of the output member beingunaffected by at least limited overstroke of the linear input member.

Another object of the present invention is the provision ofa linkagehaving an escape wheel displaceable in uniform angular increments, andin clockwise or counterclockwise directions, in response to thedisplacement of an input member in forward and reverse directionsrespectively.

Another object is the provision ofa linkage having low friction losses.

Still another object of the invention is to provide means for rotatingan output member by predetermined angular increments in response to thedisplacement of a reciprocating linear input member, the device being ofsimple construction and operation, and economical to manufacture.

Further objects will be apparent from the description to follow and theappended claims.

The objects mentioned above are accomplished by means of a mechanismincluding a reciprocating input member displaceable in a linear path,and an output member, referred to herein as an escape wheel, mounted forrotation about a central axis and having a series of discontinuitiessuch as drive pins extending from the face thereof. A pallet for drivingthe pins on the output member is coupled to a control member, which isin turn actuated by the input member. With each displacement of theinput member in a driving direction, the pallet sequentially engagesseveral of the drive pins to rotate the escape wheel, and a plurality ofthe pins engages a specially contoured surface on the control member tolimit the rotation of the escape wheel. Upon further displacement of theinput member in the driving direction, another pin on the escape wheelengages the pallet and rotates the pallet relative to the control memberto disengage the engaged pins therefrom, and maintains the escapement inthis disengaged condition while the input member is further displaced inthe driving direction until it has returned to its initial position. Byproviding the pallet and the control member with allochiralconfigurations, the escape wheel can be made to rotate in oppositedirections in response to the displacement of the input member inforward or reverse directions.

The invention, and its objects and advantages, will become more apparentin the detailed description of the preferred embodiment presented below.

BRIEF DESCRIPTION OF THE DRAWINGS In the detailed description of thepreferred embodiment of the invention presented below, reference is madeto the accompanying drawings in which:

FIGS. 1-3 depict a linkage according to the invention in threesequential stages in the operation thereof; and

FIG. 4 shows a pictorial of the invention as incorporated in a filmstripadapter mounted on a slide projector, with portions of the adapter cutaway to reveal the operative components thereof.

DETAILED DESCRIPTION OF THE INVENTION Because slide projectors are wellknown, the present description will be directed in particular toelements of slide projectors and filmstrip adapters therefor, formingpart of, or cooperating more directly with, apparatus in accordance withthe present invention. Specifically, the present invention will bedescribed as incorporated in an adapter of the type disclosed inpreviously cited Ser. No. 27,519. That adapter is intended for use withan indexing mechanism of the type disclosed in U.S. Pat. Re. No. 26,789and incorporated in a slide projector of the type disclosed in U.S. Pat.No. 3,276,314. This slide projector receives and indexes a circularslide tray for sequentially presenting slide transparencies to aprojection position, and the aforementioned adapter enables theprojector to receive filmstrip and sequentially present frames of filmthereon to a projection position. The present invention is intended toconvert a linear input from the preceding type of indexing mechanism toa rotary output for operating a filmstrip advancing mechanism. It is tobe understood that slide projector and filmstrip adapter elements notspecifically shown or described may take various forms well known tothose skilled in the art. The following description will first bedirected to the basic structure of the preferred embodiment, with thevarious elements shown in schematic form. The adaptation of theinvention to the above-mentioned apparatus will be described thereafter.The various elements of the present invention have been ascribedappellations taken from the horological art because of the similarity ofstructure or function of these elements with elements common to thatart.

Referring to the linkage illustrated in FIG. 1, an input member 2 isshown as being displaceable in a linear path on a fixed plane andreciprocal in the directions indicated by the arrows A and B from a restposition indicated by the line 0-0. A control member 4 is coupled toinput member 2 at pivot 5,

and is displaceable angularly and linearly in response to the lineardisplacement of input member 2. Control member 4 comprises a double rampportion 6 to be described below. The output member of the linkagecomprises an escape wheel 8 mounted for rotation about axis 10, and hasextending therefrom a plurality of pins designated by the sequence ofnumerals from 101 through 108. The pins are displaced radially from axis10 of escape wheel 8 by a common distance. Moreover, the pins aredisplaced from each otherby equal angular amounts. A pallet 12 iscoupled to control member 4 by means of pins 14 and 16 which extendthrough arcuate slots 18 and 20 in control member 4. Arcuate slots 18and 20 are segments of a circle. Pallet 12 has an allochiralconfiguration, and includes adjacent sets of surfaces speciallycontoured for engaging the pins extending from escape wheel 8 to rotateescape wheel 8 by equal angular increments with each reciprocation ofinput member 2, in a manner to be described below.

Double ramp portion 6 also has an allochiral configuration, andcomprises ramp surfaces 22 and 24, which are urged into engagement withthe pins extending from escape wheel 8 by means of a spring 26. Pallet12 is biased upwardly relative control member 4 by means of springs 28.The description of the invention can best be continued by way of adescription of the operation thereof.

Initially, input member 2 is in the rest position at the line 0, and adrive pin 101 is located in notch 29 defined by ramp surfaces 22 and 24of ramp portions 6, and positioned in notch 30 on pallet 12. Controlmember 4 is biased in a counterclockwise direction about pivot by spring26, whereby pin 101 is rendered under the influence of spring 26. Theinfluence of springs 28 on pallet 12 urges that element upwardly so thatpins 14 and 16 engage the uppermost portions of slots 18 and 20 incontrol member 4.

It should be understood at this point that escape wheel 8 can be rotatedin either a clockwise or counterclockwise direction, depending onwhether input member 2 is reciprocated in the directions B or Arespectively, from the line 00. For the purposes of this description,the direction A will be termed forward direction and the direction Bwill be termed the reverse direction. When input member 2 is displacedaway from the line 0-0 in either of the directions A or B, thatdirection of displacement will be termed the driving direction becauseit is this displacement which effects the rotation of escape wheel 8.Displacement of input member 2 towards the line 00 will be termed thereturn direction.

Upon the forward displacement of input member 2 in the drivingdirection, control member 4 is displaced to the right as shown by arrowC, and pallet 12, coupled to control member 4 by pins 14, 16, exerts asidewise force on pin 101 causing escape wheel 8 to rotate about axis asshown by arrow D. Upon the continued displacement of input member 2 inthe driving direction, pin 101 proceeds in a counterclockwise directionand eventually, as indicated in FIG. 2, disengages from notch 30 inpallet 12 with which it has been in driving engagement. When pin 101leaves driving engagement with notch 30, pin 102, which has beentraveling with notch 32 in pallet 12, becomes engaged with the left handsurface thereof, and the driving force on pallet 12 is now exerted toescape wheel 8 through pin 102. During this sequence, the full force ofcontrol member 4 is exerted on escape wheel 8 since pins 14 and 16 haveremained in the upper portions of slots 18 and 20 of control member 4.

As escape wheel 8 rotates with the continued displacement of inputmember 2, pin 104 engages the surface 36 on pallet 12 and pin 103 isreceived by the recess defined by surface 34. In response to thesubsequent displacement of input member 2 in the driving direction, pin103 travels towards ramp 22, and pin 104 engages surface 36 of pallet 12and proceeds to drive that surface towards ramp 22. Pin 104 thus rotatespallet 12 about pin 16 in the uppermost portion of slot 20, and pin 14in slot 18 begins to travel downwardly. The angular displacement ofescape wheel 8 is arrested when pin 103 engages ramp 22.

At this time, escape wheel 8 has been rotated by the predeterminednumber of degrees.

Even though escape wheel 8 has been rotated by the desired amount, inputmember 2 is still permitted a certain amount of overtravel in thedriving direction. Thus, as control member 4 moves to the right, pin 104imparts torque to pallet 12, and the latter rotates about pin 16 causingpin 14 to travel to the lowermost portion of slot 18. Eventually, themechanism achieves the condition shown in FIG. 3. In this condition, pin104 has rotated pallet 12 to such an extent that pin 102 has becomecompletely disengaged from notch 32. Overtravel is now possible despitethe arresting of the rotation of escape 1 wheel 8 because pin 104 holdspallet 12 down and out of engagement with pin 102. Thus, input member 2is able to proceed in the forward direction with ramp surface 22 inengagement with pins 102 and 103. However, when pin 103 reaches abuttingsurface 38 in notch 34 of pallet 12, further displacement of the controlmember 4 in the forward direction is prevented.

An alternate embodiment of the invention permits unlimited overtravel ofinput member 2 without rotation of escape wheel 8 beyond the prescribedamount. Referring to FIG. 3, it is apparent that displacement of inputmember 2 is limited by the location of abutting surface 38, since thatsurface engages pin 103 to preclude continued displacement of inputmember 2. However, by removing surface 34 and by in effect cutting off aportion of pallet 12 along a plane parallel with ramp surface 22 whenpallet 12 rotated by its maximum amount relative to ramp portion 6 (asin FIG. 3) at surface 40 (which is aligned with surface 22 and hence notvisible in FIG. 3), continued displacement of pallet 12 causes pin 103to ride along surface 40. Hence, pin 103 holds pallet 12 in its rotatedposition and escape wheel 8 rotates no further than the prescribedangular amount, so that the continued displacement of input member 2 inthe driving direction after the initial engagement of pin 103 with ramp22 causes pin 103 to travel in engagement with surface 40 the fulllength thereof. Surface 40 can be of any length, and virtual unlimitedovertravel is possible.

Upon completion of the displacement of input member 2 in the drivingdirection, it becomes necessary to return the input member to the restposition, and to maintain escape wheel 8 in its new position with pin102 having assumed the initial position of pin 101. This result isachieved by the continued engagement of pin 104 with surface 36 (or 40)to keep pallet 12 in the position in which it is disengaged from thepins extending from the escape wheel 8 (of course, excluding pin 104).Thus, while the device returns to the rest position, pins 102 and 103ride along ramp 22 towards notch 29 of the ramp. When input member 2reaches the rest position 00, pin 104 becomes disengaged from surface 36on pallet 12, and springs 26 and 28 return pallet 12 and control member6 to their initial positions.

The embodiment illustrated in FIGS. 1-3 is displaced in for clockwiseand counterclockwise rotation of escape wheel 8 in response to thelinear displacement of input member 2 in the directions A and B asmentioned previously. Accordingly, allochiral pallet 12 is provided withnotch 42, surface 44, surface 46 and surface 48, which surfacescorrespond with those designated by the numerals 32, 34, 36, and 38mentioned above. Similarly, surface 50 (shown in dotted lines)corresponds to the surface 40 mentioned earlier as an alternativeembodiment of the invention. Ramp 24 corresponds in operation with ramp22, also mentioned before. Therefore, when input member 2 is displacedin driving direction in the reverse direction B and thereafter returnedto the rest position at plane 00, the operational characteristics of thedevice are the same as those described previously, except that escapewheel 8 rotates clockwise in predetermined angular increments with eachreciprocation of input member 2.

If only unilateral rotation of the escape wheel 8 is desired, one-halfof the upper contoured surface of pallet 12, excluding notch 30, can bedispensed with. In such an embodiment,

both pins 14 and 16 would be required, since each serves a functionregardless of the rotational output of escape wheel 8.

Other variations falling within the scope of the invention can beenvisioned. The linear input member 2 has been shown in schematic formbut of course it could comprise any number of equivalent arrangements.Control member 4 is shown as being angularly displaceable relative toinput member 2, but practically speaking, a mechanical joint often isunnecessary. For example, if the member connecting ramp portion 6 andinput member 2 is long enough, and there is sufficient play in inputmember 2 in the direction transverse to the plane of movement, theslight angular displacement required of control member 4 could beachieved. Control member 4 could be connected to the linear input memberin any number of ways, and is shown in the drawings as merely beingconnected by a straight member for the sake of simplicity. Likewise,springs 26 and 28 are shown schematically, and they also could take avariety of forms. The functions of springs 26 and 28 could beaccomplished by the use of leaf springs or coil springs or the like, andtheir respective function could be divided among a plurality of springs.The angular displacement of escape wheel 8 depends on the number ofdrive pins on the surface thereof. For example, to decrease theincremental displacement of the member 8, additional pins would beadded, and pallet 12 and ramp surfaces 22 and 24 would be alteredaccordingly. It might also be noted that the functions of the input andoutput members can be reversed, so that drive force would be applieddirectly to escape wheel 8, and the output would be the resultingreciprocating motion of member 2.

As explained earlier, the present invention is particularly suitable forincorporation in an adapter for enabling circular slide tray projectorto receive and advance filmstrip. FIG. 4 illustrates a filmstrip adapter200 of the type described in Ser. No. 27,519 mounted on a slideprojector 300, the latter being representative of the projectordisclosed in U.S. Pat. No. 3,276,3l4 and incorporating an indexingmechanism of the type disclosed in U.S. Pat. Re. No. 26,789.

Adapter 200 includes a housing 202, a lens holder 204, a Filmstripholder 206, and sprocket wheels 212. Filmstrip 210 is shown loaded inadapter 200 for advancement therethrough. The advancement of filmstrip210 is accomplished by means of the rotation of sprocket wheels 212 andthe successive engagement of sprockets 214 extending from sprocketwheels 212 with perforations 216 located along the opposite lateraledges of filmstrip 210.

The rotation of sprocket wheels 212 is accomplished through a linkageaccording to the present invention. This linkage includes an arm 208coupled by a coupling 222 to an input member 224, and fastened to a rampportion 228. A pallet 230 is coupled to ramp portion 228 by means ofpins 231 and 233 extending through slots 236 and 238. Pallet 230 isfurther coupled to an escape wheel 218 by means of the engagement of thecontoured surfaces of the pallet with pins 220 extending from theforward surface of escape wheel 218. Escape wheel 218 and sprocketwheels 212 are mounted for rotation on a common axle 221, and arecoupled together so that the angular displacement of escape wheel 218results in a like angular displacement of sprocket wheels 212. It shouldbe apparent at this point that pins 220 can be spaced from one anotherby an amount such that the rotation of the escape wheel 218 by thatamount causes sprocket wheels 212 to advance filmstrip by a distanceequal to the length of one frame of film.

Projector 300 comprises an annular lip 302 in which a circular slidetray is normally received by the projector, buttons 304 and 306 foreffecting the forward and reverse indexing of a slide tray mounted onthe projector, a focusing knob 308 for adjusting the lens system of theprojector, a lens mount 310 by means of which adapter 200 is mounted onprojector 300, and an indexing mechanism including drive member 312.Drive member 312 reciprocates in radial and curved paths for normallyengaging lugs extending downwardly from the bottom a received circularslide tray and indexing the tray to present slides to a projector filmgate.

Input member 224 includes a guide member 232 having a slot 234 thereinfor engaging lip 302 of projector 300 to maintain member 224 and arm 208in position, and a connecting member 226 extending therefrom. Connectingmember 226 includes a slot 227 contoured to receive drive member 312when guide member 232 is mounted on lip 302, so that when drive member312 is driven along its indexing path, member 226 will be displacedthereby. Because of the combined length of input member 224 and arm 200,the play in coupling 222, and the short path of travel of drive member312, the movement of arm 208 in response to the indexing displacement ofmember 312 is substantially linear, so that element 224 is equivalent toinput member 2 described earlier. In fact, the curved path of drivemember 312 is short enough to be considered linear for present purposes,and that member could be considered equivalent to previously discussedmember 2.

The tolerance limits for the path of movement of drive member 312 ofprojector 300 are quite large, and the displacement of member 312 canaccordingly vary by relatively large amounts without hindering thenormal operation of the projector. However, it is important thatfilmstrip 210 be advanced in film frame length increments for the properprojection of the frames. The particular advantages of the linkageaccording to the invention as incorporated in the adapter now becomeapparent.

The dimensions of the various components of adapter 200 are selected sothat sprocket wheels 212 will necessarily be rotated by an amountsufficient to advance filmstrip 210 a distance equal to a frame lengthwhen drive element 312 moves along its minimum path of travel. And, as aresult of the overtravel feature of the invention, whenever indexingmember 312 moves along a path having a distance greater than the minimumdistance, the sprocket wheels will be rotated by the prescribed amountand no more.

In light of the discussion relating to the schematic representation ofthe invention shown in FIGS. 1-3, the operation of invention as utilizedin the apparatus shown in FIG. 4 is apparent, and will be mentioned onlybriefly. Assuming forward advancement of filmstrip 210 through adapter200 is desired, button 304 is depressed. Drive member 312 follows itsnormal prescribed path, and in so doing urges input member 224 and arm208 in the forward, driving direction. Arm 208, and ramp portion 228integral therewith, move: pallet 230 and escape wheel 218 in theirprescribed paths, thereby rotating sprocket wheels 212 by the properangular increment in the clockwise direction to advance filmstrip 210 bya distance equal to the length of a frame of film. Depression of button306 to effect the movement of drive member 312 in the path for reverseindexing similarly causes the counterclockwise rotation of sprocketwheels 212. The previous discussion of the invention fully describes thedetailed operation of the above-mentioned linkage. Reference is made toU.S. Ser. No. 27,519 and U.S. Pat. No. 3,276,314 and U.S. Pat. Re. No.26,789 for complete descriptions of adapter 200, projector 300, and theindexing mechanism, respectively.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

I claim:

1. A device for converting reciprocating linear motion into rotarymotion, said device comprising:

an input member reciprocally displaceable in a substantially linear pathin driving and return directions;

an output member comprising a first member having an axis of rotationand a forward surface, and rotatable in uniform angular increments aboutsaid axis in response to successive reciprocations of said input member;

a plurality of discontinuities arranged sequentially on said forwardsurface of said first member, said discontinuities displaced radiallyfrom said axis of rotation, and uniformly spaced from each other byangular amounts equal to said uniform angular increments;

a second member coupled to said input member and displaceable in drivingand return directions in response to like displacements of said inputmember, said second member including a control surface engageable bysaid discontinuities for limiting the rotation of said first member witheach operation of said device; a third member coupled to said secondmember and movable in at least one arcuate path relative to said secondmember, said third member comprising: driving surfaces for engaging andexerting force on said discontinuities to rotate said first member; and

at least one abutting surface engageable by said discontinuities formoving said third member in said arcuate path to disengage saiddiscontinuities from said driving surfaces in response to the rotationof said first member by the predetermined amount, and for keeping saiddriving surfaces disengaged from said discontinuities when said inputmember is further displaced in the driving direction, and when saidinput member is displaced in the return direction;

means for urging said third member in a predetermined path relative tosaid first member and into engagement with one of said discontinuitiesin said path; and

means for urging said second member in a predetermined directionrelative to said first member;

wherein in response to displacement of said second member in the drivingdirection, said driving surfaces on said third member successivelyengage the discontinuity in said path and the next discontinuity in thesequence on said first member to rotate said first member about the axisof rotation; and

wherein said control surface on said second member engages said nextdiscontinuity to limit the rotation of said first member to said uniformangular increment.

2. A device according to claim 1 wherein said third member furthercomprises blocking means for limiting the displacement of said inputmember in the driving direction after the disengagement of saiddiscontinuities from said driving surfaces.

3. A device according to claim 2 wherein said blocking means comprisesat least one surface on said third member for engaging a discontinuityengaged by said control surface on said second member, after thedisengagement of said discontinuities from said driving surfaces.

4. A device according to claim 1 further comprising:

first pin and slot means for coupling said third member and said secondmember, wherein said slot means defines said arcuate path of said thirdmember; and

second pin and slot means about which said third member is pivotal formovement in said arcuate path in response to engagement of said abuttingsurface on said third member by said discontinuities.

5. A device according to claim 1 wherein said input member isreciprocably displaceable in forward and reverse directions, each ofsaid directions having corresponding driving and return directions, saidfirst member being rotatable in clockwise and counterclockwisedirections in response to the displacement of said input member in theforward and reverse directions respectively;

wherein said second member includes first and second allochiral controlsurfaces, said surfaces being engageable by said discontinuities inresponse to the displacement of said input member in the forward andreverse directions respectively, to limit the rotation of said firstmember to said uniform angular increments;

wherein said third member comprises first and second allochiral drivingsurfaces for engaging and exerting force on said discontinuities, inresponse to the displacement of said input member in the forward orreverse directions respectively;

wherein said abutting surface on said third member comprises first andsecond allochiral abutting surfaces engageable by said discontinuitiesto limit the displacement of said input member in the drivingdirections, in

response to the displacement of said input member in the forward orreverse directions respectively; and wherein said at least one arcuatepath comprises first and second allochiral arcuate paths, said thirdmember being displaceable in one of said paths in response to theengagement of said continuities with a corresponding abutting surface onsaid third member. 6. A device according to claim 5 further comprising:first and second allochiral pin and slot means for coupling said thirdmember to said second member, wherein said slot means define said firstand second arcuate paths of movement of said third member, and whereinsaid second and first pin means are pivots about which said third memberis movable in said first and second arcuate paths respectively. 7. Adevice according to claim 6 wherein said first and second abuttingsurfaces on said second member comprise allochiral ramps meeting at thelowermost ends thereof, and inclined respectively to engage the seconddiscontinuity from said discontinuity in said path, to limit therotation of said first member to said uniform angular increment.

8. A device for converting reciprocating linear motion into rotarymotion of predetermined, uniform angular increments, said devicecomprising:

input means movable in a driving direction in a linear path in responseto the exertion of force thereon; a first member having an axis ofrotation and being mounted for rotation about said axis; a plurality ofdiscontinuities located on said first member, said discontinuities beingspaded radially from said axis of rotation by equal distances, andspaced from each other by equal angular amounts; a second member coupledto said input means and movable in a path transverse to said linear pathand into engagement with said discontinuities, said second membercomprising: driving means engageable with one of said discontinuitiesfor effecting the rotation of said first member in response to themovement of said input means in the driving direction; and

abutment means engageable with another of said discontinuities inresponse to the rotation of said first member by said predeterminedangular increment, for preventing the further rotation of said secondmember in response to the further movement of said input means in thedriving direction; and

means for urging said second member in said transverse path intoengagement with said discontinuities.

9. A device according to claim 8 wherein:

said input means is movable in forward and reverse directions in saidlinear path;

said driving means of said second member is engageable with one of saiddiscontinuities for effecting the rotation of said first member in afirst direction in response to movement of said input means in theforward direction, and for effecting the rotation of said first memberin a second direction in response to movement of said input means in thereverse direction; and

said abutment means includes first and second surfaces, each of saidsurfaces being engageable with another of said discontinuities inresponse to the rotation of said first member by said predeterminedangular increment in said first and second directions, respectively, forpreventing the further rotation of said second member in response to thefurther movement of said input means in the driving direction.

1. A device for converting reciprocating linear motion into rotarymotion, said device comprising: an input member reciprocallydisplaceable in a substantially linear path in driving and returndirections; an output member comprising a first member having an axis ofrotation and a forward surface, and rotatable in uniform angularincrements about said axis in response to successive reciprocations ofsaid input member; a plurality of discontinuities arranged sequentiallyon said forward surface of said first member, said discontinuitiesdisplaced radially from said axis of rotation, and uniformly spaced fromeach other by angular amounts equal to said uniform angular increments;a second member coupled to said input member and displaceable in drivingand return directions in response to like displacements of said inputmember, said second member including a control surface engageable bysaid discontinuities for limiting the rotation of said first member witheach operation of said device; a third member coupled to said secondmember and movable in at least one arcuate path relative to said secondmember, said third member comprising: driving surfaces for engaging andexerting force on said discontinuities to rotate said first member; and,at least one abutting surface engageable by said discontinuities formoving said third member in said arcuate path to disengage saiddiscontinuities from said driving surfaces in response to the rotationof said first member by the predetermined amount, and for keeping saiddriving surfaces disengaged from said discontinuities when said inputmember is further displaced in the driving direction, and when saidinput member is displaced in the return direction; means for urging saidthird member in a predetermined path relative to said first member andinto engagement with one of said discontinuities in said path; and meansfor urging said second member in a predetermined direction relative tosaid first member; wherein in response to displacement of said secondmember in the driving direction, said driving surfaces on said thirdmember successively engage the discontinuity in said path and the nextdiscontinuity in the sequence on said first member to rotate said firstmember about the axis of rotation; and wherein said control surface onsaid second member engages said next discontinuiTy to limit the rotationof said first member to said uniform angular increment.
 2. A deviceaccording to claim 1 wherein said third member further comprisesblocking means for limiting the displacement of said input member in thedriving direction after the disengagement of said discontinuities fromsaid driving surfaces.
 3. A device according to claim 2 wherein saidblocking means comprises at least one surface on said third member forengaging a discontinuity engaged by said control surface on said secondmember, after the disengagement of said discontinuities from saiddriving surfaces.
 4. A device according to claim 1 further comprising:first pin and slot means for coupling said third member and said secondmember, wherein said slot means defines said arcuate path of said thirdmember; and second pin and slot means about which said third member ispivotal for movement in said arcuate path in response to engagement ofsaid abutting surface on said third member by said discontinuities.
 5. Adevice according to claim 1 wherein said input member is reciprocablydisplaceable in forward and reverse directions, each of said directionshaving corresponding driving and return directions, said first memberbeing rotatable in clockwise and counterclockwise directions in responseto the displacement of said input member in the forward and reversedirections respectively; wherein said second member includes first andsecond allochiral control surfaces, said surfaces being engageable bysaid discontinuities in response to the displacement of said inputmember in the forward and reverse directions respectively, to limit therotation of said first member to said uniform angular increments;wherein said third member comprises first and second allochiral drivingsurfaces for engaging and exerting force on said discontinuities, inresponse to the displacement of said input member in the forward orreverse directions respectively; wherein said abutting surface on saidthird member comprises first and second allochiral abutting surfacesengageable by said discontinuities to limit the displacement of saidinput member in the driving directions, in response to the displacementof said input member in the forward or reverse directions respectively;and wherein said at least one arcuate path comprises first and secondallochiral arcuate paths, said third member being displaceable in one ofsaid paths in response to the engagement of said continuities with acorresponding abutting surface on said third member.
 6. A deviceaccording to claim 5 further comprising: first and second allochiral pinand slot means for coupling said third member to said second member,wherein said slot means define said first and second arcuate paths ofmovement of said third member, and wherein said second and first pinmeans are pivots about which said third member is movable in said firstand second arcuate paths respectively.
 7. A device according to claim 6wherein said first and second abutting surfaces on said second membercomprise allochiral ramps meeting at the lowermost ends thereof, andinclined respectively to engage the second discontinuity from saiddiscontinuity in said path, to limit the rotation of said first memberto said uniform angular increment.
 8. A device for convertingreciprocating linear motion into rotary motion of predetermined, uniformangular increments, said device comprising: input means movable in adriving direction in a linear path in response to the exertion of forcethereon; a first member having an axis of rotation and being mounted forrotation about said axis; a plurality of discontinuities located on saidfirst member, said discontinuities being spaced radially from said axisof rotation by equal distances, and spaced from each other by equalangular amounts; a second member coupled to said input means and movablein a path transverse to said linear path and into engagement with saiddiscontinuIties, said second member comprising: driving means engageablewith one of said discontinuities for effecting the rotation of saidfirst member in response to the movement of said input means in thedriving direction; and abutment means engageable with another of saiddiscontinuities in response to the rotation of said first member by saidpredetermined angular increment, for preventing the further rotation ofsaid second member in response to the further movement of said inputmeans in the driving direction; and means for urging said second memberin said transverse path into engagement with said discontinuities.
 9. Adevice according to claim 8 wherein: said input means is movable inforward and reverse directions in said linear path; said driving meansof said second member is engageable with one of said discontinuities foreffecting the rotation of said first member in a first direction inresponse to movement of said input means in the forward direction, andfor effecting the rotation of said first member in a second direction inresponse to movement of said input means in the reverse direction; andsaid abutment means includes first and second surfaces, each of saidsurfaces being engageable with another of said discontinuities inresponse to the rotation of said first member by said predeterminedangular increment in said first and second directions, respectively, forpreventing the further rotation of said second member in response to thefurther movement of said input means in the driving direction.